Shovel having a wristing dipper

ABSTRACT

A rope shovel includes a wristing dipper arrangement. The shovel comprises a base, a boom extending from the base, the boom having a first end attached to the base and a second end remote from the base. The shovel further comprises a pulling mechanism mounted on the second end of the boom and a boom attachment pivotally mounted on the boom and attached to a dipper, the boom attachment including an actuator coupled to the dipper.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of prior-filed, co-pending U.S.application Ser. No. 13/362,939, filed Jan. 31, 2012, which claims thebenefit of and priority to U.S. Provisional Patent Application No.61/438,475, filed Feb. 1, 2011. The entire contents of these documentsare hereby incorporated by reference herein.

BACKGROUND

The present invention relates to rope shovels used in the mining and theconstruction industries.

In the mining field, and in other fields in which large volumes ofmaterials must be collected and removed from a work site, it is typicalto employ a power shovel including a large dipper for shoveling thematerials from the work site. After filling the dipper with material,the shovel swings the dipper to the side to dump the material into amaterial handling unit, such as a dump truck or a local handling unit(e.g., crusher, sizer, or conveyor). Generally, the shovels used in theindustry include hydraulic shovels and electric rope shovels.Conventional electric rope shovels typically include a dipper diggingcomponent rigidly connected to the dipper handle. This configurationallows the digging attachment to have only two degrees of freedom ofmovement in the dig path of the dipper: hoist and crowd.

SUMMARY

In one embodiment, a mining shovel includes a base and a boom extendingfrom the base. The boom includes a lower end attached to the base and anupper end remote from the base. A pulling mechanism is mounted on theupper end of the boom. A boom attachment has a first end pivotallycoupled to the boom and a second end attached to a dipper, the dippermoveably supported by the pulling mechanism. A dipper actuator iscoupled between the boom attachment and the dipper. The dipper actuatoris operable to pivot the dipper relative to the boom attachment.

In other embodiments, a mining shovel includes a base, a boom having afirst boom end coupled to the base and a second boom end, and a pullingmechanism at the second boom end. A boom attachment includes a firstportion coupled to the boom between the first boom end and the secondboom end, and a second portion pivotally coupled to the first portionand supported by the pulling mechanism. A dipper is coupled to thesecond portion of the boom attachment.

In still other embodiments, a mining shovel includes a base, a boomhaving a first boom end coupled to the base and a second boom end, and apulling mechanism at the second boom end. A boom attachment has a firstportion coupled to the boom between the first boom end and the secondboom end, and a second portion pivotally coupled to the first portionand supported by the pulling mechanism. A boom attachment actuatorextends between the boom attachment and at least one of the base and theboom. The boom attachment actuator is operable to pivot the boomattachment relative to the boom. A dipper is pivotally coupled to thesecond portion of the boom attachment, and a dipper actuator is coupledbetween the boom attachment and the dipper and is operable to pivot thedipper relative to the boom attachment.

Other aspects of the invention will become apparent by consideration ofthe detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a rope shovel according to an embodiment of theinvention.

FIG. 2 is a perspective view of an electric rope shovel according toanother embodiment of the invention.

FIG. 3 is a perspective view of an electric rope shovel according to yetanother embodiment of the invention.

FIG. 4 is a perspective view an electric rope shovel according toanother embodiment of the invention.

It is to be understood that the invention is not limited in itsapplication to the details of the construction and the arrangements ofcomponents set forth in the following description or illustrated in thedrawings. The present invention is capable of other embodiments and ofbeing practiced or being carried out in various ways. Also, it is to beunderstood that the phraseology and terminology used herein is for thepurpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

Conventional electric rope shovels cannot “wrist” the dipper during theinitial penetration of the bank of material like hydraulic shovels can.Hydraulic shovels typically possess three degrees of freedom whiledigging: hoist, crowd, and bucket wrist. These hydraulic shovelsdemonstrate excellent initial bank penetration at the lower dig heights.Hydraulic shovels, however, lose efficiency later in the dig path cycle.As they rake the bank at higher dig heights, they struggle to keep digforces high at the bucket teeth. The reason for the weak effort higherin the bank is that the hydraulic shovels must lift the combined weightsof the boom, handle, dipper, and material, whereas the electric shoveldoes not need to lift the boom.

On the other hand, electric rope shovels demonstrate excellent digforces higher in the bank because they utilize the boom point sheave orpulley located high above the ground and away from the dipper. Electricrope shovels use this boom point sheave as a pulley, translating hoistdrum torque into rope bail pull in a direction that directly lifts andhoists the dipper load through the bank and into the air. This generatesvery efficient and powerful dig forces at the dipper teeth. However,because the dipper in conventional electric rope shovels is fixedrelative to the dipper arm, the ability to create high digging forceswhen the dipper is low to the ground is limited by the fixed geometry ofthe dipper arm, the boom, and the relative locations of the shippershaft and the boom point sheave.

Thus, there is a need for an electric rope shovel that incorporates thehoist force of the boom point pulley of an electric shovel, with thedipper wristing feature of a hydraulic shovel. This improved electricshovel provides a highly efficient and versatile digging attachment thatcan operate efficiently in all types of bank conditions.

FIGS. 1-4 illustrate rope shovels 10 according to various embodiments ofthe present invention. Like parts are identified using the samereference numbers. Referring to FIG. 1, the rope shovel 10 includes alower base 15 that is supported on drive tracks 20, and an upper base 25(also called a deck) positioned on a rotational structure 30 that ismounted to the lower base 15. The rotational structure 30 allowsrotation of the upper base 25 relative to the lower base 15. The upperbase 25 includes, among other elements, an operating area 33 in which anoperator or a driver sits to operate the rope shovel 10.

The rope shovel 10 further includes a boom 45 extending upwardly andforwardly from the upper base 25. The boom 45 includes a first end 46coupled to the upper base 25 and a distal second end 47. The illustratedboom 45 is curved and has “banana” or a “V” shape, while the curved boom45 offers certain advantages, other embodiments may include asubstantially straight boom. The boom 45 includes a lower attachmentpoint 26 where the boom 45 is coupled to the upper base 25 by pin jointsor other suitable attachment mechanisms. The boom 45 also includes anupper attachment point 54 to which a support strut 48 is connected. Thesupport strut 48 extends downwardly and rearwardly from the upperattachment point 54 and is coupled to the upper base 25. Together thestrut 48, upper base 25, and boom 45 define a substantially rigidtriangulated structure that supports the boom 45 in an uprightorientation.

The illustrated curved boom 45 includes a generally vertical firstportion 31 that extends generally upwardly from the base 25, and anangled second portion 32 that extends at an angle from the first portion31 toward the second end 47 of the boom. The first portion 31 of theboom 45 is angled with respect to the second portion 32 of the boom. Insome embodiments, the angle between the first portion 31 and the secondportion 32 of the boom can be between about one hundred and twentydegrees and about one hundred and sixty degrees. More specifically, theangle between the first portion 31 and the second portion 32 can bebetween approximately one hundred and sixty degrees. In other words, thesecond portion 32 of the boom 45 is offset between about twenty andabout sixty degrees from the first portion 31 of the boom 45. Inparticular, the offset between the second portion 32 of the boom 45 andthe first portion 31 can be twenty degrees. The illustrated boom 45 isof a one piece construction combining the first and the second portions31, 32 of the boom. In other embodiments, the boom 45 can be formed fromtwo or more separate pieces joined by welding, pin joints, fasteners, orany other attachment mechanisms.

The rope shovel 10 also includes a digging attachment comprising a boomattachment 50 (also called a boom handle) pivotally coupled to the boom45 and a dipper 55 pivotally coupled to the boom attachment 50. Thedipper 55 includes dipper teeth 56 and is used to excavate the desiredwork area, collect material, and transfer the collected material to adesired location (e.g., a material handling vehicle). The boomattachment 50 is pivotally mounted to the boom 45 at a first pivotlocation 42, and the dipper 55 is pivotally mounted to the boomattachment 50 at a second pivot location 49. In the illustratedembodiment, the first pivot location 42 is positioned generally wherethe first portion 31 and the second portion 32 of the boom 45 connect orintersect.

The illustrated boom attachment 50 includes a first or upper arm 64 anda second or lower arm 65 pivotally coupled to the upper arm at a thirdpivot location 51. The upper arm 64 is pivotally coupled to the boom 45at the first pivot location 42, and the dipper 55 is pivotally coupledto the lower arm 65 at the second pivot location 49. The pivotalconnections between the upper and lower arms 64, 65 and the dipper 55provide a multi-degree-of-freedom system that allows the dipper 55 to bemaneuvered through a range of motion that includes the dashed-linerepresentation of the upper and lower arms 64, 65 and the dipper 55 inFIG. 1. This range of motion is greater than a conventional rope shovelhaving a rigid boom attachment 50 and a fixed dipper 55. While theillustrated embodiment shows the first, second, and third pivotlocations 42, 49, and 51 as pin joints, other mechanical connectionssuch as cams, linkages, gear sets, and the like may also be used toachieve the desired relative movement between the upper arm 64, thelower arm 65, and the dipper 55. In this regard, the “pivot locations”may not necessarily be located on or coincide with a structural portionof the rope shovel 10, but may instead be located at a fixed or moveablelocation in space as defined by the specific mechanical connectionbetween the respective components.

The illustrated rope shovel 10 includes a plurality of hydrauliccylinders for controlling movement of the boom attachment 50 and thedipper 55. The boom attachment 50 is controlled by a first actuator inthe form of a first hydraulic cylinder 66 having a first end coupled tothe base 25 and a second end coupled to a mounting point 67 on the upperarm 64 of the boom attachment 50. The dipper 55 is controlled by asecond actuator in the form of a second hydraulic cylinder 71 having afirst end coupled to the third pivot location 51 and a second endcoupled to a mounting point 68 on the dipper 55. The first hydrauliccylinder 66 is therefore operable to pivot the upper arm 64 about thefirst pivot location 42 relative to the base 25 and boom 45, and thesecond hydraulic cylinder 71 is operable to pivot the dipper 55 aboutthe second pivot location 49 relative to the lower arm 65.

The second hydraulic cylinder 71 provides a controllable force on thedipper 55 for creating forward and backward movement of the dipper 55.Thus, the second hydraulic cylinder 71 allows the dipper 55 to “wrist”during travel through the digging path of the shovel 10. Wristing thedipper during penetration of the bank of material allows for quicker andmore efficient collection of material and gives the shovel operator theversatility needed for selective and forceful digging in the bank. Itshould be noted that second hydraulic cylinder 71 can be substitutedwith other mechanical devices and structures. For example, pivoting rackand pinion systems, pneumatic cylinders, pistons, electric motors andthe like can also be used to move the dipper 55. These alternativemechanisms can also be used to replace the first hydraulic cylinder 66.Thus, the entire digging attachment can be manufactured without anyhydraulics, if desired.

The boom 45 includes a pulling mechanism 58 mounted at the second end 47of the boom 45. In some embodiments, the pulling mechanism 58 comprisesa pulley or boom sheave 60. A flexible hoist rope 62 is attached to aconnecting portion 73 of the boom attachment 50 and at least partiallysupports the boom attachment 50 and the dipper 55. In other embodiments(not shown), the hoist rope 63 can be directly attached to the dipper55. For example, the rope 63 can be attached to the dipper connectingelement 57. The flexible hoist rope extends from the connecting portion73 (or the connecting element 57), over the sheave 60 and is thenwrapped around a hoist drum 63 that is mounted on the upper base 25 ofthe electric shovel 10. The flexible hoist rope 62 may be or include oneor more than one rope that may pass over the sheave 60 multiple times.In this regard, the connecting portion 73 may be or include an equalizercapable of equalizing the load on the various ropes 62 or rope portionsthat support the dipper 55. The hoist drum 63 is powered by an electricmotor (not shown) that provides turning torque to the drum 63 through ageared hoist transmission (not shown).

The sheave 60 is rotatably coupled to the second end 47 of the boom 45between a pair of sheave support members 37 located at the second end 47of the boom 45 (only one of the sheave support members 37 is visible inFIG. 1). A rod or a load pin 34 extends between the sheave supportmembers 37 and through the sheave 60, thereby rotatably coupling thesheave 60 to the boom 45. Thus, the sheave 60 rotates about the rod orthe load pin 34. In other embodiments, alternative mechanisms forconnecting the sheave 60 to the boom 45 can be used. Rotation of thehoist drum 63 reels in and pays out the hoist rope 62, which travelsover the sheave 60 and raises and lowers the dipper 55.

A common feature of the illustrated embodiments is that if the hoistrope 62 is removed, the boom attachment 50 will have one unrestraineddegree-of-freedom associated with the third pivot location 51. Thus, thefirst and second hydraulic cylinders 66, 71 cannot, by themselves, fullycoordinate movement of the boom attachment 50 and the dipper 55. Rather,it is combined operation of the first and second hydraulic cylinders 66,71 and the hoist rope 62 that allows for complete control of the boomattachment 50 and dipper 55.

In operation, the boom attachment 50 that extends from the boom 45 isdriven by the first hydraulic cylinder 66 positioned on the base 25.Using that force, the upper 64 arm of the boom attachment drives thelower arm 65 by utilizing the pinned connection at the third pivotlocation 51. Rotating the upper arm 64 thrusts the lower arm 65 and thedipper 55 into the bank of material. This constitutes crowd force.Rotation or wristing of the dipper 55 is provided by the secondhydraulic cylinder 71, which is mounted between the boom attachment 50and the dipper 55. At the same time, the pulley 60 and hoist drum 63cooperate to apply forces to the hoist rope 62 that lift the dipper 55through the bank of material and into the air. The dipper 55 issimultaneously driven by the boom attachment 50 and the hoist forcegenerated by the rope 62 driven by the hoist drum 63 and over the pulley60. Thus, the shovel 10 possesses three degrees of digging freedom:hoist, crowd, and bucket wrist.

The above-described combined and coordinated operation of the hoist drum63 and hoist rope 62 with the first and second hydraulic cylinders 66,71 provide efficient digging forces throughout the range of motion ofthe boom attachment 50 and dipper 55. For example, when the boomattachment 50 and dipper 55 are in the position shown in dashed lines inFIG. 1, compared to the hoist rope 62, the hydraulic cylinders 66, 71are in a position of superior mechanical advantage for driving thedipper 55 generally forwardly into the bank. After the boom attachment50 and dipper 55 are pushed into the bank and moved further away fromthe lower base 15, compared to the hydraulic cylinders 66, 71, the hoistrope 62 occupies a position of superior mechanical advantage for raisingthe dipper generally vertically through the bank of material. Thus, bycoordinating operation of the hydraulic cylinders 66, 71 and the hoistrope 62, strong, efficient dig forces can be maintained throughout therange of motion of the boom attachment 50 and dipper 55.

FIGS. 2-4 illustrate alternative embodiments of the rope shovel 10 that,other than the specific differences discussed below, are generallysimilar in configuration and operation to the rope shovel 10 of FIG. 1.

Because FIGS. 2-4 are perspective views, the specific structure of thestrut 48 is more fully shown in FIGS. 2-4. The strut 48 entirelyreplaces the gantry structure used in many conventional shovels. In someembodiments, the strut 48 includes two parallel strut legs 49 coupled byrigid-connect members 51. One end 52 of the strut 48 is coupled to thebase 25 at a location spaced apart from the first end 46 of the boom 45.A second end 53 of the strut 48 is coupled to the boom 45 by connectingeach strut leg 49 to the upper attachment point 54 of the boom 45. Insome embodiments, the second end 53 of the strut 48 is coupled to thegeneral area where the first portion 31 and the second portion 32 of theboom 45 connect or intersect. The strut 48 supports the boom 45 in theupright position.

In some embodiments, the strut 48 is pivotally connected to the base 25and to the boom 45 via moving pin joints or other types of connectors.During shovel operation, the strut 48 can be exposed to both compressionand tension loads and forces. Therefore, the strut 48 can be providedwith shock absorbing connectors such as various types of springassemblies incorporated into the pinned attachment joints between thestrut 48, the base 25, and the boom 45. These shock absorbing connectorscan reduce the overall stiffness of the strut assembly when compressionand tension forces are acting on the strut, thereby reducing oreliminating shock loading and in turn reducing the overall stressesexperienced by the various components.

FIGS. 2-4 also show that the upper arm 64 comprises a pair of spacedapart upper arm members 43, and the lower arm 65 comprises a pair ofspaced apart lower arm members 39. The embodiments of FIGS. 2 and 3include a boom 45 having a pair of spaced apart boom members 44. The twoboom members 44 are attached to and extend from the upper base 25, andthe first hydraulic cylinder 66 extends through the space between thetwo boom members 44 and between the pair of upper arm members 43 forcoupling to the mounting point 67. The embodiment of FIG. 4, on theother hand, includes a substantially solid boom first portion 31 and apair of first hydraulic cylinders 66 are positioned on each side of theboom 45 and extend to mounting points 67 associated with each of theupper arm members 43. As also shown in FIG. 4, the mounting points 67are on the underside of the upper arm members 43, or below an imaginaryline drawn between the first and third pivot locations 42, 51. In FIGS.1-3, the mounting point(s) 67 are located above an imaginary line drawnbetween the first and third pivot locations 42, 51. Thus, the specificconfiguration and arrangement of the first hydraulic cylinder (s) 66 canvary depending upon, among other things, the specific configuration ofthe boom 45 and the upper arm 64.

Similarly, the specific configuration and arrangement of the secondhydraulic cylinder 71, which can include more than one hydrauliccylinder, can vary depending upon the specific configuration andarrangement of the lower arm 65 and the dipper 55. For example, in FIG.1, the second hydraulic cylinder 71 has one end coupled to the thirdpivot location 51. In other embodiments, such as the embodiments ofFIGS. 2 and 4, the second hydraulic cylinder(s) 71 can be coupled to thelower arm 65 at a second mounting location 79. The second mountinglocation 79 can be either above (FIG. 2) or below (FIG. 4) an imaginaryline drawn between the second and third pivot locations 49, 51. Onebenefit of the embodiments of FIGS. 1 and 2, where the second hydrauliccylinder 71 is positioned above the lower arm 65, is that if the lowerarm 65 accidentally strikes a loading vehicle or other structure duringoperation, the hydraulic cylinder 71 is less likely to be damaged. Instill other embodiments, such as the embodiment of FIG. 3, the secondhydraulic cylinders 71 can be coupled to the upper arm 64, such that thesecond mounting location 79 is located on the upper arm 64. Otherembodiments can include various other intermediate structures throughwhich the second hydraulic cylinders 71 can be attached to the upper arm64 or the lower arm 65. Further, in some embodiments, the hydrauliccylinders 71 are attached to the lower portion of the dipper 55 (FIGS. 3and 4). In other embodiments, the hydraulic cylinders 71 can be attachedto the upper portion of the dipper 55 (FIGS. 1 and 2).

Various features and advantages of the invention are set forth in thefollowing claims.

What is claimed is:
 1. A mining shovel comprising: a base including ahoist drum for paying out and reeling in a hoist rope; a boom includinga first end coupled to the base and a second end opposite the first end,the hoist rope extending over the second end of the boom; a boomattachment movably coupled to the boom, the boom attachment rotatablerelative to the boom about a first pivot location, the first memberincluding a first end and a second end; an excavating member including afirst portion and a second portion, the excavating member defining amaterial discharging opening and a material receiving opening, the firstportion pivotably coupled to the second end of the boom attachment, thesecond portion pivotably coupled to the first portion to selectivelyclose the material discharging opening; and a pivot actuator for movingthe excavating member relative to the second end of the boom attachment,the pivot actuator including a first end coupled to the boom attachment.2. The shovel of claim 1, wherein the excavating member is coupled tothe hoist rope passing over the second end of the boom.
 3. The shovel ofclaim 2, wherein the hoist rope exerts a tension force on the excavatingmember, thereby inducing a moment on the excavating member to rotateabout the second end of the boom attachment in a first direction.
 4. Theshovel of claim 3, wherein the pivot actuator is a hydraulic cylindersuch that extension of the cylinder causes the excavating member torotate about the second end of the boom attachment in the firstdirection.
 5. The shovel of claim 3, wherein the tension force acts onthe excavating member at a first joint and the excavating member ispivotably coupled to the second end of the boom attachment at a wristjoint that is offset from the first joint.
 6. The shovel of claim 5,wherein operation of the pivot actuator changes the offset distancebetween the wrist joint and the first joint, thereby changing the momentinduced by the tension force acting on the excavating member.
 7. Theshovel of claim 1, wherein the first portion of the excavating member ispivotably coupled to the boom attachment at a wrist joint, and whereinthe pivot actuator further includes a second end coupled to theexcavating member at a second joint that is offset from the wrist joint.8. The shovel of claim 1, wherein the excavating member is a dipper, thefirst portion being a dipper body and the second portion being a dipperdoor.
 9. A mining shovel comprising: a boom including a first end and asecond end opposite the first end; a hoist rope extending substantiallyalong the boom and passing over the second end of the boom; a handlemoveably coupled to the boom, the handle rotatable relative to the boomabout a first pivot location, the handle including a first end and asecond end; an excavating member pivotably coupled to the second end ofthe handle at a wrist joint, the excavating member coupled to the hoistrope passing over the second end of the boom, the hoist rope exerting atension force on the excavating member at a position that is offset fromthe wrist joint, the tension force inducing a moment on the excavatingmember to rotate the excavating member about the wrist joint in a firstdirection; and an actuator including a first end coupled to the handleand a second end coupled to the bucket proximate a lower end of theexcavating member, extension of the pivot actuator causing theexcavating member to rotate about the wrist joint in the firstdirection.
 10. The shovel of claim 9, wherein the excavating memberfurther includes a first portion and a second portion, the secondportion having a pair of side walls and a lower wall extending betweenthe side walls, the second portion defining a material receiving openingand a material discharging opening opposite the material receivingopening, the first portion being pivotably coupled to the first portionto selectively close the material discharging opening.
 11. The shovel ofclaim 10, wherein the excavating member further includes a plurality ofteeth positioned along at least a portion of an edge of the lower wallproximate the material receiving opening.
 12. The shovel of claim 8,wherein extension of the pivot actuator changes an offset distancebetween the tension force and the wrist joint, thereby changing themoment induced by the tension force.
 13. The shovel of claim 8, whereinthe excavating member is a dipper, the first portion being a dipper bodyand the second portion being a dipper door.